Michele Gordigiani

Michele Gordigiani was an Italian painter, known best for his portraits. Gordigiani was the son of a famous Florentine musician, he first studied at the Academy in Florence under Giuseppe Bezzuoli Luigi Norcini and Silvestro Lega. In 1855, he frequented the Caffè Michelangiolo along with his brother Anatolio, where he met many of the Macchiaioli painters, he painted a portrait of the Piedmontese painter, Ludovico Raymond, who spent time at the Caffè. He was invited to Paris in 1860 by Virginia Oldoini, the Countess of Castiglione, he was in much demand as a portrait painter, among his subjects were King Vittorio Emanuele II, his daughter-in-law Queen Margherita, the Count of Cavour. In 1867 in London, he painted portraits of Queen Victoria, her consort, Prince Albert, he painted portraits of Elizabeth and her husband Robert Browning, now in the National Portrait Gallery. In London, he participated at the exhibition of the Royal Society of Arts. Due to his friendship with Luigi Mussini, he was a member of the commission for the triennial contest for painting at the Sienese institute of Art.

In this period, his colleagues and friends included the writers and intellectuals Andrea Maffei, Edmondo De Amicis, Enrico Nencioni. He painted costume genre subjects, as well as mythology, small landscapes, his genre scenes did not prove commercially successful. In 1896 he sent works to the Florentine Exhibition of Art and Flowers and at the Second Venice Biennale. In 1909 moved to America, where he continued to work as a portrait artist. Among his pupils were Fosco Tricca, Francesca Magliani, Pompeo Massani, Alfredo Müller

Brownout (electricity)

A brownout is an intentional or unintentional drop in voltage in an electrical power supply system. Intentional brownouts are used for load reduction in an emergency; the reduction lasts for hours, as opposed to short-term voltage sag. The term brownout comes from the dimming experienced by incandescent lighting. A voltage reduction may be an effect of disruption of an electrical grid, or may be imposed in an effort to reduce load and prevent a power outage, known as a blackout. In some countries, the term brownout refers not to a drop in voltage but to an intentional or unintentional power outage. Different types of electrical apparatus will react in different ways to a sag; some devices will be affected, while others may not be affected at all. The heat output of any resistance device, such as an electric space heater, is equal to the true power consumption, an increasing function of the applied voltage. If the resistance stays constant, power consumption is proportional to the square of the applied voltage.

Therefore, a significant reduction of heat output will occur with a small reduction in voltage. An incandescent lamp will dim due to lower heat creation in the filament, as well as lower conversion of heat to light. Speaking, no damage will occur but functionality will be impaired. Commutated electric motors, such as universal motors, will run at reduced speed or reduced torque. Depending on the motor design, no harm may occur. However, under load, the motor may draw more current due to the reduced back-EMF developed at the lower armature speed. Unless the motor has ample cooling capacity, it may overheat and burn out. An induction motor will draw more current to compensate for the decreased voltage, which may lead to overheating and burnout. If a substantial part of a grid's load is electric motors, reducing voltage may not reduce load and can result in damage to customers' equipment. An unregulated direct current supply will produce a lower output voltage for electronic circuits; the output ripple voltage will decrease in line with the reduced load current.

In a CRT television, the reduced output voltage can be seen as the screen image shrinking in size and becoming dim and fuzzy. A linear direct current regulated supply will maintain the output voltage unless the brownout is severe and the input voltage drops below the drop out voltage for the regulator, at which point the output voltage will fall and high levels of ripple from the rectifier/reservoir capacitor will appear on the output. A switched-mode power supply which has a regulated output will be affected; as the input voltage falls, the current draw will increase to maintain the same output voltage and current, until such a point that the power supply malfunctions. Brownouts can cause unexpected behaviour in systems with digital control circuits. Reduced voltages can bring control signals below the threshold at which logic circuits can reliably detect which state is being represented; as the voltage returns to normal levels the logic can latch at an incorrect state. The seriousness of this effect and whether steps need to be taken by the designer to prevent it depends on the nature of the equipment being controlled.

Dumsor Power outage Black start